feat(phase-6): Next.js UI + TypeScript strict + 백엔드 mypy 설정

UI:
- web/lib/api.ts: 백엔드 모든 엔드포인트의 클라이언트 + 타입 (Symbol,
  ChartPayload, PredictResponse, LatestPredictionResponse, MetricsResponse,
  NewsResponse). NEXT_PUBLIC_API_BASE 자동 정규화.
- web/components/SearchBox: 디바운스 검색, seed_only 토글, trigram + prefix.
- web/components/StockChart: lightweight-charts 캔들 + 예측 overlay
  (median dashed + q10/q90 점선). base_date 에서 target_date 까지 이어 붙임.
- web/components/PredictionPanel: "예상차트 보기" 버튼 → POST /api/predict
  → user_triggered=TRUE 저장 → onResult 콜백으로 StockChart 에 반영.
  표로 +1/+3/+5거래일 direction, prob_up/flat/down, expected_return,
  ci_low~ci_high 표시.
- web/components/MetricsPanel: 최근 30일 hit_rate / mae.
- web/components/NewsList: 최근 뉴스 + 감성 라벨/점수.
- web/app/page.tsx: 검색 페이지.
- web/app/[code]/page.tsx: 종목 상세 (차트 + 패널 + 메트릭 + 뉴스).

TypeScript 보강 (사용자 요청 "typescript도 추가해서 나중에 수정하기 쉽게"):
- tsconfig.json: strict 외에 forceConsistentCasingInFileNames,
  noFallthroughCasesInSwitch, noImplicitOverride 추가.
- package.json: typecheck (tsc --noEmit), check (typecheck + lint) 스크립트,
  eslint + eslint-config-next 14.2.3.
- .eslintrc.json: next/core-web-vitals.
- package-lock.json 커밋 (재현 가능한 dep).

백엔드:
- pyproject.toml: [tool.mypy] 추가. strict_optional, no_implicit_optional,
  check_untyped_defs. 3rd-party stub 없는 pykrx/chronos 등은 ignore.

검증: `npx tsc --noEmit` 통과 (exit=0).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

web/components/NewsList.tsx

@@ -0,0 +1,77 @@
+"use client";
+
+import { useEffect, useState } from "react";
+import { api, type NewsResponse } from "../lib/api";
+
+export function NewsList({ code }: { code: string }) {
+  const [data, setData] = useState<NewsResponse | null>(null);
+  const [err, setErr] = useState<string | null>(null);
+
+  useEffect(() => {
+    let alive = true;
+    api
+      .news(code, 20)
+      .then((r) => {
+        if (alive) setData(r);
+      })
+      .catch((e) => {
+        if (alive) setErr(e instanceof Error ? e.message : String(e));
+      });
+    return () => {
+      alive = false;
+    };
+  }, [code]);
+
+  if (err) return <div className="text-xs text-red-400">뉴스 로딩 실패: {err}</div>;
+  if (!data) return <div className="text-xs text-zinc-500">뉴스 로딩 중…</div>;
+  if (!data.items.length)
+    return <div className="text-xs text-zinc-500">최근 뉴스 없음</div>;
+
+  return (
+    <div className="rounded-md border border-zinc-800 bg-zinc-900/40 p-4">
+      <div className="mb-2 text-sm font-medium text-zinc-200">최근 뉴스/공시</div>
+      <ul className="divide-y divide-zinc-800">
+        {data.items.map((n, i) => (
+          <li key={i} className="py-2">
+            <a
+              href={n.url}
+              target="_blank"
+              rel="noopener noreferrer"
+              className="block hover:bg-zinc-800/40"
+            >
+              <div className="text-sm text-zinc-100 line-clamp-2">{n.title}</div>
+              <div className="mt-0.5 flex items-center gap-2 text-xs text-zinc-500">
+                <span>{n.source}</span>
+                {n.published_at && <span>· {formatDate(n.published_at)}</span>}
+                {n.sentiment_label && (
+                  <span className={sentimentColor(n.sentiment_label)}>
+                    · {n.sentiment_label} {n.sentiment_score != null ? `(${n.sentiment_score.toFixed(2)})` : ""}
+                  </span>
+                )}
+              </div>
+            </a>
+          </li>
+        ))}
+      </ul>
+    </div>
+  );
+}
+
+function sentimentColor(l: string): string {
+  if (l === "positive") return "text-emerald-400";
+  if (l === "negative") return "text-red-400";
+  return "text-zinc-400";
+}
+
+function formatDate(iso: string): string {
+  try {
+    const d = new Date(iso);
+    return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())} ${pad(d.getHours())}:${pad(d.getMinutes())}`;
+  } catch {
+    return iso;
+  }
+}
+
+function pad(n: number): string {
+  return n < 10 ? `0${n}` : `${n}`;
+}